Re: Lost all Data

From:

Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>

Date:

Tue, 11 Aug 2009 10:13:40 -0700 (PDT)

:but my /dev on the second disk has more files than /dev on the first disk.
:I have updated the base system on the second disk also using chroot .
:Is it because i have not booted from the second disk after the upgade?
It's just because DEVFS is mounted on one and not mounted on
the other. With DEVFS we no longer need anything in the dev
directory since the DEVFS mount will simply overload it. An
all-new installation of the system will leave the original /dev
in the filesystem (prior to mounting DEVFS) empty.
An upgrade leaves the original contents of /dev intact.. not because
I want it to be intact (I'd rather delete it)... but because it is
difficult to delete it on a live system since we can't unmount DEVFS.
The only way to delete would be to do a localhost NFS export for /,
mount it somewhere else, and then the original /dev would be exposed
and accessible for deletion.
So, simply put, you have DEVFS mounted on top of one filesystem
but not on top of the other. The original contents of <fs>/dev
is no longer relevant to the system now that we have DEVFS.
If you want to mount DEVFS in both places you can do so with
mount_devfs, or even mount_null.
-Matt